burton



(No Model.) 3 Sheets-S1 1eet 1.

G. D. BURTON & E. E. ANGELL. METHOD OF AND APPARATUS FOR ELECTRIC METALHEATING.

No. 537,009. Patented Apr. 9, 1895.

WFT E5555. l \/E 'TE1F\S (No Model.) 3 SheetsSheet 2.

G. D. BURTON 8: E. E. ANGELL. METHOD OF AND APPARATUS FOR ELECTRIC METALHEATING.

No. 537,009 Patented Apr. 9,1895.

Wrrrl E5555. Ma 7 (No Model.) 3 Sheets-Sheet 3.

G. D. BURTON & E. E. ANGELL. METHOD OF AND APPARATUS FOR ELECTRIC METALHEATING.

N0. 537,009. Patented Apr. 9, 1895.

,5 whey.

UNITED STATES PATENT OFFICE.

GEORGE D. BURTON, OF BOSTON, AND EDWIN E. ANGELL, OF SOMERYILLE,MASSACHUSETTS, ASSIGNORS, BY MESNE ASSIGNMENTS, TO SAID BURTON.

METHOD OF AND APPARATUS FOR ELECTRIC METAL-HEATING.

SPECIFICATION forming part of Letters Patent No. 537,009, dated April 9,1 895.

Application filed August 30, 1892. Serial No. 444,538. (No model.)

To ctZZ whom it may concern/.-

Be it known that we, GEORGE DEXTER TON, residing at Boston, in thecounty of Suffolk, and EDWIN ELLIOTT ANGELL, residing 5 at Somerville,in the county of Essex, in the State of Massachusetts, citizens of theUnited States of America, have invented certain new and usefulImprovements in Apparatus for Electric Metal-Heating, of which thefollowing is a specification.

This invention relates to a closed forge for heating metals for forgingand tempering purposes, the inclosure of the bars or other forms ofmetal to be heated serving to decrease the I time and economize thepower required for heating.

The object of the invention is to provide an apparatus of this characterin which the bars may be inserted and withdrawn with facility andquickly.

Figure l of the accompanying drawings represents a perspective view ofthis improved electric forge. Fig. 2 represents a perspective view of asimilar closed electric forge,

2 wherein the inclosing casing is shown as composed in part of firebrick. Fig. 3 represents a longitudinal vertical section of the closedelectric forge. Fig. 4 represents a form of electrode foraclosedelectric forge adapted for 0 heating square barsor pieces of metal. Fig.5 represents a form of electrodes for a closed electric forge adapted toheat fiat bars or plates of metal. Fig. 6 represents a side elevation ofa device for inclosing a single bar 5 during the heating operation. Fig.7 represents a transverse section thereof.

The same reference numbers indicate the same parts in all the figures.

In heating metals by electricity with this apparatus, the bar, ingot, orother piece of metal, or the portion thereof to be heated, is inclosedwithin a closed chamber whereby free access of air and radiation of heatare prevented. An electric heating current is then 4 5 passed throughthe inclosed metal to be heated until the desired forging or othertemperature is attained, and then said metal is removed from theinclosure and subjected to the desired forging, shaping or tempering 5ooperation.

A closed electric forge adapted for one or more bars or pieces of metalmay be employed in carrying out this process. The closed forgerepresented in Fig. 1 of the accompanying drawings comprises a box 10the sides and bottom of which are composed of asbestos boards or othersuitable non-conductor of elec tricity and a top 15 preferably composedof mica, glass or other suitable transparent material, which will permitthe inspection of the metal being heated during theheating operation.

Electrodes 20 and 30 composed of copper or other suitable conductivematerial are dis posed in and may constitute the opposite ends of thebox 10. These electrodes are in the form of rectangular plates and arepreferably of less breadth than the height of the box, non-conductivestrips being disposed above them and forming a flush surface with theupper edges of the sides of the box.

The electrode 20 is provided with a tang 21 which projects outward forconnection with the electric source, and on its inner face saidelectrode is provided with sockets 22 which may be round, square,angular, conical or other shape, for receiving the inner ends of thebars or other pieces of metal to be heated. The electrode 30 is providedwith a depending tang 31 which extends through the 11011- conductivebottom of the box for connection with the other terminal of the electricsource. This electrode is provided with a number of eyes 32corresponding in shapeto the bars to be heated and disposed opposite thesockets 22 of the electrode 20.

The top 15, which is shown in the form of a transparent dome is cementedto the upper edges of the box 10, or otherwise fastened to said box.

The electrodes are detachable from the box, the edges thereof beingpreferably beveled so as to be readily adjusted in the ends of the box.

Several sets of electrodes may be provided for each closed forge, thedifferent sets having holes and sockets of different sizes and shapes tosuit the different sizes and shapes of the bars. This interchangeabilityof the electrodes avoids dismantling the forge when bars of differentsizes or shapes are to be heated.

The electrodes are connected with any suitable source of a heatingcurrent by any suitable conductors. As shown in Figs. 1 and 2 theelectrode 20 is connected by a vertical rod 25 and a bracket 26 with aring which constitutes one pole of an electric current converter similarto that shown in the patent of the United States, No. 475,232, grantedto the Electrical Forging Company on the invention of Burton, Eddy andBriggs, dated May 17, 1892. The electrode 30 is connected by means ofconductors 35, 36 and 37 with a bracket 56 connected with a ringconstituting the other pole of said converter.

The box 10 of the closed forge shown in Fig. 2 is constructed of firebrick and a table 60 having a refractory or non-conductive surfaceserves as a support for the closed forge.

A cooling pipe constructed of non-conductive material such as fiberboard or rubber through which the conducting rods 25 and 37 pass, isshown in Fig. 1. Ablower or force pump 71 is connected with said pipe 70and serves to force a cooling fluid, as air, into contact with saidconductors whereby overheating thereof is prevented, and the conductionof heat to the converter is avoided.

Instead of the converter shown a dynamo or storage battery adapted tosupply a heating current of large volume and low voltage may be used.

In the use of the closed forge shown in Figs. 1 and 2 the bar to beheated is thrust through an eye 32 of the electrode 30 into the closedbox 10 until its inner end rests in one of the sockets :22 of theelectrode 20. The contact of the bar with both electrodes closes thecircuit between them, and the heavy heating current passes through thatportion of the bar which extends between the electrodes within theinclosure. As many bars maybe inserted as there are eyes and sockets.\Vhen the entire capacity of the forge is not used, the re maining eyesmaybe closed by plugs to prevent access of air. The metal attains a redheat in a few seconds and the oxygen contained in the box is consumedand the heating will then be conducted in a partial vacuum.

The closed forge shown in Figs. 6 and 7 may be in the form of a tubecomposed of metal or preferably of a transparent non-conductivesubstance provided with non conductive ends having openings for thepassage of the bar to be heated. This closed forge can be applied to asingle bar, and the electrodes may be connected with the bar outside theends of the tube, if desired.

Ve find that in the process of heating where the heat of the bar isconfined within an inclosure, that rapid heating of the conductors isavoided and that the heating of the material is accomplished with fromten to fifteen per cent. less power than where the heating is done bythe electric current in the open air.

In this process of heating, the bar is heated 65 from its interior, theheat being conducted outward and there is very little scaling at thesurface of the metal. In the ordinary heating of bars by coal, gas oroil fires, a loss by sealing amounting to nine per cent. occurs, whereasour experiments show that the loss by scale in our process varies from1.56 to 2.1 per cent, whereby a large saving is effected.

While we show the heating receptacle for the metal, in the shape of asquare box, it is obvious that it may be of any shape suitable to themetal to be heated. It may be found advisableto stand the metal on oneend; in which case in the heating of large bars, the weight of the barwhile resting on end would give a solid contact upon the electrode.

\Ve claim as our invention 1. In an electric forge, the combination of areceptacle provided with an inwardly flaring socket and opposite saidsocket with an outwardly flaring eye, and means connected with electricpoles of opposite polarity for conveying a current of large volume to abar supported in said eye and socket.

2. In an electric forge, the combination of a receptacle provided withan electrode set in the wall thereof and provided with means forsupporting the end of the bar to be heated, and an electrode set in anopposite wall and provided with an outwardly flaring eye.

3. In an electric forge, the combination of a receptacle provided withan electrode set in the wall thereof and having an inwardly flaring eyeor socket, and an electrode set in an opposite wall and provided with anoutwardly flaring eye or socket.

at. In an electric forge, the combination of an electric heatingreceptacle, an electrode therein adapted to receive and support one endof a bar to be heated, and a detachable electrode constituting a part ofthe wall of said box and provided with an outwardly flaring eye forsupporting another part. of the bar to be heated.

5. In an electric forge, the combination of an electric heatingreceptacle provided with an electrode to fit in the wall thereof andhaving a series of inwardly flaring eyes or sockets, and an electrodeset in an opposite wall and provided with a series of outwardly flaringeyes or sockets.

6. In an electric forge, the combination of an inclosed body composed inpart of insulating material and in part of copper the copper partconstituting electrodes connected with opposite electric poles and beingprovided with eyes and sockets, and a transparent top surmounting saidbody.

GEO. D. BURTON. EDWIN E. ANGELL. Witnesses:

CHAS. FoLLEN ADAMS, WALLACE HAoKuTT.

